Field of the Invention
The invention relates to an engine control device applied to a vehicle comprising a suspension control device and an internal combustion engine and capable to automatically stop an operation of the engine and start the operation of the engine (restart the operation of the engine).
Description of Related Art
Conventionally, a suspension control device is known. The suspension control device electrically controls a suspension property of a vehicle such as a vehicle height and a damping force of a shock absorber. The suspension control device includes an actuator. The actuator is, for example, a stepping motor for changing a damping force of a shock absorber for damping the vibration of a vehicle body by increasing and/or decreasing the opening degree of a damping force control valve of the shock absorber. Such a shock absorber may get a situation where a damping force of the shock absorber based on a command value from a suspension control device to a stepping motor is not consistent with an actual damping force of the shock absorber. Such a situation is referred to as a “step-out.” When a step-out occurs, it may lead to a problem such as degradation of a ride quality of a vehicle, for example.
Accordingly, one of the conventional techniques resolves a step-out by outputting a command value which exceeds an upper or lower limit of a control range when a command value for an actuator (for example, stepping motor) of a shock absorber corresponds to the upper or lower limit (for example, refer to JP 2010-064582 A). Thereby, a step-out can be resolved in a short time and unpleasant sensation that a passenger feels while the step-out is being resolved can be minimized.
On the other hand, in recent years, a device for improving the fuel consumption of the engine by automatically stopping the operation of the engine when a predetermined engine operation stop condition is satisfied (that is, the automatic stop and start control device of the engine) has been employed (for example, refer to JP 2006-329122 A and JP 2013-036343 A). Hereinafter, the automatic stop and start control device of the engine may be simply referred to as “the engine control device”.